Designing for Efficiency
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4. Simulation Methodology
Transient simulation is configured to reach steady state before measurements are taken.
4.1 Steady-State Window
Converters exhibit startup transients as capacitors charge and control loops settle. Efficiency must be measured only after
waveforms repeat periodically.
The reference simulation displays synchronized plots of efficiency, input/output power, device losses, and output electrical
behavior. These waveforms allow engineers to correlate switching behavior with measured loss mechanisms. The measured
signals correspond to key electrical nodes in the schematic of Figure 1.
Figure 2: Transient simulation of the push-pull converter showing synchronized plots of overall efficiency, input-output power, diode loss,
switch loss, and output voltage/current measured over a steady-state interval.
4.2 Automated Measurement Expressions
Trace expressions compute time-averaged power over a fixed cursor window, ensuring repeatable comparisons.
4.3 Controlled Comparison
Both Si and SiC simulations use identical:
f
Input voltage
f
Load conditions
f
Switching frequency
f
Transformer parameters
Only semiconductor models differ.
